Re: [PATCH v7 3/5] crash: Use crash_exclude_core_ranges() on powerpc

[Sourabh Jain]

On 28/02/26 06:51, Jinjie Ruan wrote:

On 2026/2/27 22:50, Sourabh Jain wrote:

Resend of:
https://lore.kernel.org/all/19cf18b5-362d-4ff2-8b85-e2e728092...@linux.ibm.com/

On 26/02/26 18:34, Jinjie Ruan wrote:

The crash memory exclude of crashk_res and crashk_cma memory on powerpc
are almost identical to the generic crash_exclude_core_ranges().

By introducing the architecture-specific arch_crash_exclude_mem_range()
function with a default implementation of crash_exclude_mem_range(),
and using crash_exclude_mem_range_guarded as powerpc's separate
implementation, the generic crash_exclude_core_ranges() helper function
can be reused.

Acked-by: Mike Rapoport (Microsoft) <r...@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjin...@huawei.com>
---
   arch/powerpc/kexec/ranges.c | 16 ++++------------
   include/linux/crash_core.h  |  4 ++++
   kernel/crash_core.c         | 19 +++++++++++++------
   3 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
index 6c58bcc3e130..e5fea23b191b 100644
--- a/arch/powerpc/kexec/ranges.c
+++ b/arch/powerpc/kexec/ranges.c
@@ -553,9 +553,9 @@ int get_usable_memory_ranges(struct crash_mem
**mem_ranges)
   #endif /* CONFIG_KEXEC_FILE */
     #ifdef CONFIG_CRASH_DUMP
-int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
-                       unsigned long long mstart,
-                       unsigned long long mend)
+int arch_crash_exclude_mem_range(struct crash_mem **mem_ranges,
+                 unsigned long long mstart,
+                 unsigned long long mend)

update_crash_elfcorehdr() in arch/powerpc/kexec/crash.c still calls
crash_exclude_mem_range_guarded(), causing a build failure.

ld: arch/powerpc/kexec/crash.o: in function `update_crash_elfcorehdr':
/root/linux/arch/powerpc/kexec/crash.c:454: undefined reference to
`crash_exclude_mem_range_guarded'


To fix this:
--------------
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index 898742a5205c..e59e909c369d 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -451,7 +451,7 @@ static void update_crash_elfcorehdr(struct kimage
*image, struct memory_notify *
                 base_addr = PFN_PHYS(mn->start_pfn);
                 size = mn->nr_pages * PAGE_SIZE;
                 end = base_addr + size - 1;
-               ret = crash_exclude_mem_range_guarded(&cmem, base_addr,
end);
+              ret = arch_crash_exclude_mem_range(&cmem, base_addr, end);
                 if (ret) {
                         pr_err("Failed to remove hot-unplugged memory
from crash memory ranges\n");
                         goto out;

With the above change included, things are working fine on powerpc.

It seems the declaration of crash_exclude_mem_range_guarded() added in
arch/powerpc/include/asm/kexec_ranges.h can also be removed.

Yes, lets remove it.

   {
       struct crash_mem *tmem = *mem_ranges;
   @@ -604,18 +604,10 @@ int get_crash_memory_ranges(struct crash_mem
**mem_ranges)
               sort_memory_ranges(*mem_ranges, true);
       }
   -    /* Exclude crashkernel region */
-    ret = crash_exclude_mem_range_guarded(mem_ranges,
crashk_res.start, crashk_res.end);
+    ret = crash_exclude_core_ranges(mem_ranges);
       if (ret)
           goto out;
   -    for (i = 0; i < crashk_cma_cnt; ++i) {
-        ret = crash_exclude_mem_range_guarded(mem_ranges,
crashk_cma_ranges[i].start,
-                          crashk_cma_ranges[i].end);
-        if (ret)
-            goto out;
-    }
-
       /*
        * FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
        *        regions are exported to save their context at the time of
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index 033b20204aca..dbec826dc53b 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -68,6 +68,7 @@ extern int crash_prepare_elf64_headers(struct
crash_mem *mem, int need_kernel_ma
                          void **addr, unsigned long *sz);
   extern int crash_prepare_headers(int need_kernel_map, void **addr,
                    unsigned long *sz, unsigned long *nr_mem_ranges);
+extern int crash_exclude_core_ranges(struct crash_mem **cmem);
     struct kimage;
   struct kexec_segment;
@@ -88,6 +89,9 @@ extern int kimage_crash_copy_vmcoreinfo(struct
kimage *image);
   extern unsigned int arch_get_system_nr_ranges(void);
   extern int arch_crash_populate_cmem(struct crash_mem *cmem);
   extern int arch_crash_exclude_ranges(struct crash_mem *cmem);
+extern int arch_crash_exclude_mem_range(struct crash_mem **mem,
+                    unsigned long long mstart,
+                    unsigned long long mend);
     #else /* !CONFIG_CRASH_DUMP*/
   struct pt_regs;
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 96a96e511f5a..300d44ad5471 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -287,24 +287,31 @@ unsigned int __weak
arch_get_system_nr_ranges(void) { return 0; }
   int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return
-1; }
   int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) {
return 0; }
   -static int crash_exclude_core_ranges(struct crash_mem *cmem)
+int __weak arch_crash_exclude_mem_range(struct crash_mem **mem,
+                    unsigned long long mstart,
+                    unsigned long long mend)
+{
+    return crash_exclude_mem_range(*mem, mstart, mend);
+}
+
+int crash_exclude_core_ranges(struct crash_mem **cmem)
   {
       int ret, i;
         /* Exclude crashkernel region */
-    ret = crash_exclude_mem_range(cmem, crashk_res.start,
crashk_res.end);
+    ret = arch_crash_exclude_mem_range(cmem, crashk_res.start,
crashk_res.end);
       if (ret)
           return ret;
         if (crashk_low_res.end) {
-        ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
crashk_low_res.end);
+        ret = arch_crash_exclude_mem_range(cmem,
crashk_low_res.start, crashk_low_res.end);
           if (ret)
               return ret;
       }
         for (i = 0; i < crashk_cma_cnt; ++i) {
-        ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
-                          crashk_cma_ranges[i].end);
+        ret = arch_crash_exclude_mem_range(cmem,
crashk_cma_ranges[i].start,
+                           crashk_cma_ranges[i].end);
           if (ret)
               return ret;
       }
@@ -331,7 +338,7 @@ int crash_prepare_headers(int need_kernel_map,
void **addr, unsigned long *sz,
       if (ret)
           goto out;
   -    ret = crash_exclude_core_ranges(cmem);
+    ret = crash_exclude_core_ranges(&cmem);
       if (ret)
           goto out;